ASMBS Allied Health Nutritional Guidelines for the Surgical Weight Loss Patient

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Surgery for Obesity and Related Diseases 4 (2008) S73-S108

                                                               ASMBS Guidelines

  ASMBS Allied Health Nutritional Guidelines for the Surgical Weight
                           Loss Patient
                  Allied Health Sciences Section Ad Hoc Nutrition Committee:
    Linda Aills, R.D. (Chair)a, Jeanne Blankenship, M.S., R.D.b, Cynthia Buffington, Ph.D.c,
                   Margaret Furtado, M.S., R.D.d, Julie Parrott, M.S., R.D.e,*
                                                              a
                                                                Private practice, Reston, Virginia
                                       b
                                           University of California, Davis Medical Center, Sacramento, California
                                                 c
                                                   Florida Hospital Celebration Health, Celebration, Florida
                                              d
                                                Johns Hopkins Bayview Medical Center, Baltimore, Maryland
                                                            e
                                                              Private practice, Fort Worth, Texas
                                                     Received March 11, 2008; accepted March 12, 2008

   This document is intended to provide an overview of the                       nutrition assessment should be conducted preoperatively by
elements that are important to the nutritional care of the                       a dietitian, physician, and/or well-informed, qualified mul-
bariatric patient. It is not intended to serve as training, a                    tidisciplinary team to identify the patient’s nutritional and
statement of standardization, or scientific consensus. It                        educational needs. It is essential to determine any pre-
should be viewed as an educational tool to increase aware-                       existing nutritional deficiencies, develop appropriate dietary
ness among medical professionals of the potential risk of                        interventions for correction, and create a plan for postoper-
nutritional deficiencies common to bariatric surgery pa-                         ative dietary intake that will enhance the likelihood of
tients.                                                                          success.
   The goal of this document is to provide suggestions for                           The management of postoperative nutrition begins pre-
conducting a nutrition assessment, education, supplementa-                       operatively with a thorough assessment of nutrient status, a
tion, and follow-up care. These suggestions are not man-                         strong educational program, and follow-up to reinforce im-
dates and should be treated with common sense. When                              portant principals associated with long-term weight loss
needed, exceptions should be made according to individual                        maintenance. A comprehensive nutrition evaluation goes far
variations and the evaluation findings. It is intended to                        beyond assessing the actual dietary intake of the bariatric
present a reasonable approach to patient nutrition care and                      patient. It takes into account the whole person, encompass-
at the same time allow for flexibility among individual                          ing several multidisciplinary facets. Not only should the
practice-based protocols, procedures, and policies. Amend-                       practitioner review the standard assessment components
ments to this document are anticipated as more research,                         (i.e., medical co-morbidities, weight history, laboratory val-
scientific evidence, resources, and information become                           ues, and nutritional intake), it is also important to evaluate
available.                                                                       other issues that could affect nutrient status, including readi-
                                                                                 ness for change, realistic goal setting, general nutrition
                                                                                 knowledge, as well as behavioral, cultural, psychosocial,
Nutrition care
                                                                                 and economic issues.
   The Dietitian’s role is a vital component of the bariatric                        The role of nutrition education and medical nutrition
surgery process. Nutrition assessment and dietary manage-                        therapy in bariatric surgery will continue to grow as tools
ment in surgical weight loss have been shown to be an                            to enhance surgical outcome and long-term weight loss
important correlate with success [1,2]. A comprehensive                          maintenance are explored further and identified. The fol-
                                                                                 lowing tables suggest the possible components of bariat-
                                                                                 ric nutrition care:
   *Reprint requests: American Society for Metabolic and Bariatric Sur-
gery, 100 SW 75th Street, Suite 201, Gainesville, FL 32607.                             Table 1: Suggested preoperative nutrition assessment
   E-mail: info@asmbs.org                                                               Table 2: Suggested preoperative nutrition education
1550-7289/08/$ – see front matter © 2008 American Society for Metabolic and Bariatric Surgery. All rights reserved.
doi:10.1016/j.soard.2008.03.002
S74                                       L. Aills et al. / Surgery for Obesity and Related Diseases 4 (2008) S73-S108

Table 1
Suggested Preoperative Nutrition Assessment
Recommended                                                                           Suggested                          Other considerations

Anthropometrics
  Age, sex, race, accurate height and weight, BMI, excess body weight                 Visual inspection of hair,         Waist circumference
                                                                                        skin, and nails                  Other body measurements
Weight history
 Failed weight loss attempts                                                          Life events that may have          Personal weight loss goals
 Recent preoperative weight loss attempt (if required by program)                       caused weight change

Medical history
 Current co-morbidities                                                               Past medical history               Observation of body fat
 Current medications                                                                  If available: % body fat using       distribution
 Vitamin/mineral/herbal supplements                                                      bioelectrical impedance;        Consideration of patients who
 Food allergies/intolerances                                                             resting metabolic rate            are athletic or muscular and
                                                                                         (volume of oxygen uptake);        BMI classifications
                                                                                         respiratory quotient
Available laboratory values

Psychological history
  History of eating disorder
  Current/past psychiatric diagnosis

Other
  Alcohol/tobacco/drug use
  Problems with eyesight
  Problems with dentition
  Literacy level
  Language barrier

Dietary intake: food/fluid
  24-hr recall (weekday/weekend),                                                     Cultural diet influences           Computerized nutrient analysis
  Food frequency record, or                                                           Religious diet restrictions          (if available)
  Food, mood, and activity log (helps identify food group omission or                 Meal preparation skill level       Food preferences
     dietary practices that increase nutritional risk)                                Craving/trigger foods              Attitudes toward food
  Restaurant meal intake                                                              Eats while engaged in other
  Disordered eating patterns                                                            activities

Physical activity
  Physical conditions limiting activity                                               Types of activities enjoyed in     Activity preference for the future
  Current level of activity                                                             the past                         Attitude toward physical activity
                                                                                      Amount of time spent in
                                                                                        daily sedentary activities

Psychosocial
  Motivation/reasons for seeking surgical intervention                                Confidence to maintain             Attitude toward lifestyle change
  Readiness to make behavioral, diet, exercise, and lifestyle changes                   weight loss                      Attitude toward taking life-long
  Previous application of above principles listed to demonstrate ability to           Anticipated life changes             vitamin supplementation
    make lifestyle change                                                             Marital status/children
  Willingness to comply with program protocol                                         Support system
  Emotional connection with food                                                      Work schedule
  Stress level and coping mechanisms                                                  Financial constraints
  Identify personal barriers to postoperative success                                 Referral to appropriate
                                                                                        professionals for
                                                                                        specialized physical
                                                                                        activity instruction and/or
                                                                                        mental health evaluation

  BMI ⫽ body mass index.
L. Aills et al. / Surgery for Obesity and Related Diseases 4 (2008) S73-S108                                 S75

Table 2
Suggested Preoperative Nutrition Education
Recommended                                                          Suggested                                  Other considerations

Discuss/include
  Importance of taking personal responsibility for self-             Realistic goal setting                     Appropriate monitoring of weight loss
    care and lifestyle choices                                       Benefits of physical activity
  Techniques for self-monitoring and keeping daily food
    journal
  Preoperative diet preparation (if required by program)

Postoperative intake                                                 Common complaints                          Long-term maintenance
  Adequate hydration                                                 Dehydration                                Self-monitoring
  Texture progression                                                Nausea/vomiting                            Nutrient dense food choices for
  Vitamin/mineral supplements                                        Anorexia                                     disease prevention
  Protein supplements                                                Effects of ketosis                         Restaurants
  Meal planning and spacing                                          Return of hunger                           Label reading
  Appropriate carbohydrate, protein, and fat intake, and             Stomal obstruction from food               Healthy cooking techniques
     food/fluid choices to maximize safe weight loss,                Dumping syndrome                           Relapse management
     nutrient intake, and tolerance                                  Reactive hypoglycemia
  Concepts of intuitive eating                                       Constipation
  Techniques and tips to maximize food and fluid                     Diarrhea/steatorrhea
     tolerance                                                       Flatulence/bowel sounds
  Possibility of nutrient malabsorption and importance of            Lactose intolerance
     supplement compliance                                           Alopecia
  Possibility of weight regain

       Table 3: Suggested postoperative follow-up                             mentation, or nutritional complications arising from pre-
       Table 4: Suggested biochemical monitoring tools for                    existing deficiencies. Additional laboratory measures
         nutrition status                                                     might be required and are defined by the presence of the
       Table 5: Suggested postoperative vitamin supplemen-                    existing individual co-morbid conditions. They are not
         tation                                                               included in Table 4. Table 4 is a sample of laboratory
                                                                              measures that programs might consider using to compre-
   These suggestions, included in Tables 1-5, have been                       hensively monitor patients’ nutrition status. It is not a
based on committee consensus and current research that has                    mandate or guideline for laboratory testing.
documented the pre- and postoperative likelihood of nutri-
tion deficiency [1–18].                                                       Vitamin supplementation (Table 5)
Biochemical monitoring for nutrition status (Table 4)                            Table 5 is an example of a supplementation regimen.
                                                                              As advances are made in the field of bariatrics and
    Deficiencies of single vitamins are less often encountered                nutrition, updates regarding supplementation suggestions
than those of multiple vitamins. Although protein– calorie un-                are expected. This information is intended for life-long
dernutrition can result in concurrent vitamin deficiency, most                daily supplementation for routine postoperative patients
deficiencies are associated with malabsorption and/or incom-                  and is not intended to treat deficiencies. Information on
plete digestion related to negligible gastric acid and pepsin,                treating deficiencies can be found in the Appendix “Iden-
alcoholism, medications, hemodialysis, total parenteral nutri-                tifying and Treating Micronutrient Deficiencies.” A pa-
tion, food faddism, or inborn errors of metabolism. Bariatric                 tient’s individual co-morbid conditions or changes in
surgery procedures specifically alter the absorption pathways                 health status might require adjustments to this regimen.
and/or dietary intake. Symptoms of vitamin deficiency are
commonly nonspecific, and physical examination might not be
reliable for early diagnosis without laboratory confirmation.                 Rationale for recommendations
Most characteristic physical findings are seen late in the course             Importance of multivitamin and mineral supplementation
of nutrient deficiency [17].
    Laboratory markers are considered imperative for                             It is common knowledge that a comprehensive bariatric
completing the initial nutrition assessment and follow-up                     program includes nutritional supplementation guidance,
for surgical weight loss patients. Established baseline                       routine monitoring of the patient’s physical/mental well-
values are important when trying to distinguish between                       being, laboratory values, and frequent counseling to rein-
postoperative complications, deficiencies related to sur-                     force nutrition education, behavior modification, and prin-
gery, noncompliance with recommended nutrient supple-                         ciples of responsible self-care. As the popularity of surgical
S76                                   L. Aills et al. / Surgery for Obesity and Related Diseases 4 (2008) S73-S108

Table 3
Suggested Postoperative Nutrition Follow-up
Recommended                                                       Suggested                                          Other considerations

Anthropometric
  Current and accurate height, weight, BMI, and                   Overall sense of well-being                        Use of contraception to avoid
    percentage of excess body weight                                                                                   pregnancy

Biochemical                                                       Activity level                                     Psychosocial
  Review laboratory findings when available                       Amount, type, intensity, and                       Changing relationship with food
                                                                    frequency of activity                            Changes in support system
                                                                                                                     Stress management
                                                                                                                     Body image
Medication review
 Encourage patients to follow-up with PCP regarding
    medications that treat rapidly resolving co-
    morbidities (e.g., hypertension, diabetes mellitus)

Vitamin/mineral supplements
  Adherence to protocol

Dietary intake
  Usual or actual daily intake                                    Estimated caloric intake of usual or               Promote anti-obesity foods
  Protein intake                                                    actual intake                                      containing:
  Fluid intake                                                    Reinforce intuitive eating style to                Omega-3 fatty acids
  Assess intake of anti-obesity foods                               improve food tolerance                           High fiber
  Food texture compliance                                         Appropriate meal planning                          Lean quality protein sources
  Food tolerance issues (e.g., nausea/vomiting,                                                                      Whole fruits and vegetables
     “dumping”)                                                                                                      Foods rich in phytochemicals and
  Appropriate diet advance                                                                                             antioxidants
  Address individual patient complaints                                                                              Low-fat dairy (calcium)
  Address lifestyle and educational needs for long                                                                   Discourage pro-obesity processed
     term weight loss maintenance                                                                                      foods containing:
                                                                                                                     Refined carbohydrates
                                                                                                                     Trans and saturated fatty acids

  BMI ⫽ body mass index; PCP ⫽ primary care physician.

interventions for morbid obesity continues to grow, concern                    consume sufficient amounts of unprocessed foods that are
is increasing regarding the long-term effects of nutritional                   high in vitamins and minerals, such as fruits and vegetables,
deficiencies. Nutritional complications that remain undiag-                    fish and other protein sources, dairy products, whole grains,
nosed and untreated can lead to adverse health conse-                          nuts and legumes. Poor dietary selection and habits, coupled
quences and loss of productivity. The benefits of weight loss                  with the reduced vitamin and mineral content of foods, can
surgery must be balanced against the risk of developing                        lead to micronutrient deficiencies among the general public
nutritional deficiencies to provide appropriate identification,                that interfere with body weight control, increasing the risk
treatment, and prevention.                                                     of weight gain and obesity. Therefore, a daily vitamin and
    Vitamins and minerals are essential factors and co-fac-                    mineral supplement is likely to be of value in ensuring
tors in numerous biological processes that regulate body                       adequate intake of micronutrients for maximal functioning
size. They include appetite, hunger, nutrient absorption,                      of those processes that help to regulate appropriate body
metabolic rate, fat and sugar metabolism, thyroid and adre-
                                                                               weight.
nal function, energy storage, glucose homeostasis, neural
                                                                                   Taking daily micronutrient supplements and eating foods
activities, and others. Thus, micronutrient “repletion”
                                                                               high in vitamins and minerals are important aspects of any
(meaning the body has sufficient amounts of vitamins and
                                                                               successful weight loss program. For the morbidly obese,
minerals to perform these functions) is not only important
for good health, but also for maximal weight loss success                      taking vitamin and mineral supplements is essential for
and long-term weight maintenance.                                              appropriate micronutrient repletion both before and after
    Obtaining micronutrients from food is the most desirable                   bariatric surgery. Studies have found that 60 – 80% of mor-
way to ensure the body has sufficient amounts of vitamins                      bidly obese preoperative candidates have defects in vitamin
and minerals. However, some experts have suggested that                        D [19 –22]. Such defects would reduce dietary calcium
most individuals in our “fast-paced, eat-out” society fail to                  absorption and increase a substance known as calcitriol,
Table 4
Suggested Biochemical Monitoring Tools for Nutrition Status
Vitamin/mineral    Screening        Normal range       Additional laboratory   Critical range           Preoperative deficiency      Postoperative           Comments
                                                       indexes                                                                       deficiency

B1 (thiamin)       Serum thiamin    10–64 ng/mL        2RBC transketolase      Transketolase activity   15–29%; more common in       Rare, but occurs with   Serum thiamin responds to
                                                       1Pyruvate                 ⬎20%                     African Americans and        RYGB, AGB, and          dietary supplementation
                                                                               Pyruvate ⬎1 mg/dL          Hispanics; often             BPD/DS                  but is poor indicator of
                                                                                                          associated with poor                                 total body stores
                                                                                                          hydration
B6 (pyridoxine)    PLP              5–24 ng/mL         RBC glutamic pyruvate   PLP ⬍3 ng/mL             Unknown                      Rare                    Consider with unresolved

                                                                                                                                                                                            L. Aills et al. / Surgery for Obesity and Related Diseases 4 (2008) S73-S108
                                                        Oxaloacetic                                                                                            anemia; diabetes could
                                                          transaminase                                                                                         influence values
B12 (cobalamin)    Serum B12        200–1000 pg/mL     1Serum and urinary      Serum B12                10–13%; may occur with       Common with             When symptoms are
                                                          MMA                  ⬍200 pg/mL deficiency      older patients and those     RYGB in absence         present and B12 200–
                                                       1Serum tHcy             ⬍400 pg/mL                 taking H2 blockers and       of                      250 pg/mL, MMA and
                                                                                 suboptimal               PPIs                         supplementation,        tHcy are useful; serum
                                                                               sMMA ⬎0.376 ␮mol/L                                      12–33%                  B12 may miss 25–30%
                                                                               ␮MMA ⬎3.6 ␮mol/                                                                 of deficiency cases
                                                                                 mmol CRT
                                                                               tHcy ⬎13.2 ␮mol/L
Folate             RBC folate       280–791 ng/mL      Urinary FIGLU           RBC folate               Uncommon                     Uncommon                Serum folate reflects
                                                         Normal serum and      ⬍305 nmol/L                                                                     recent dietary intake
                                                         urinary MMA             deficiency,                                                                   rather than folate status;
                                                         1Serum tHcy           ⬍227 nmol/L anemia                                                              RBC folate is a more
                                                                                                                                                               sensitive marker
                                                                                                                                                             Excessive supplementation
                                                                                                                                                               can mask B12 deficiency
                                                                                                                                                               in CBC; neurologic
                                                                                                                                                               symptoms will persist
Iron               Ferritin         Males:             2Serum iron             Ferritin ⬍20 ng/mL       9–16% of adult women in      20–49% of patients;     Low Hgb and Hct are
                                     15–200 ng/mL      1TIBC                   Serum iron ⬍50 ␮g/dL       general population are       common with             consistent with iron
                                     Females:                                  TIBC ⬎450 ␮g/dL            deficient                    RYGB for                deficiency anemia in
                                     12–150 ng/mL                                                                                      menstruating            stage 3 or stage 4
                                                                                                                                       women (51%), and        anemia; ferritin is an
                                                                                                                                       patients with super     acute phase reactant and
                                                                                                                                       obesity (49–52%)        will be elevated with
                                                                                                                                                               illness and/or
                                                                                                                                                               inflammation; oral
                                                                                                                                                               contraceptives reduce
                                                                                                                                                               blood loss for
                                                                                                                                                               menstruating females
Vitamin A          Plasma retinol   20–80 ␮g/dL        RBP                     Plasma retinol ⬍10       Uncommon; up to 7% in        Common (50%) with       Ocular finding may
                                                                                 ␮g/dL                    some studies                 BPD/DS after 1 yr,      suggest diagnosis
                                                                                                                                       up to 70% at 4 yr;
                                                                                                                                       may occur with
                                                                                                                                       RYGB/AGB

                                                                                                                                                                                            S77
S78
Table 4
Continued
Vitamin/mineral      Screening          Normal range         Additional laboratory       Critical range              Preoperative deficiency         Postoperative             Comments
                                                             indexes                                                                                 deficiency

Vitamin D            25(OH)D            25–40 ng/mL          2Serum phosphorus           Serum 25(OH)D ⬍20           Common; 60–70%                  Common with BPD/          With deficiency, serum
                                                             1Alkaline phosphatase         ng/mL suggests                                              DS after 1 yr; may        calcium may be low or
                                                             1Serum PTH                    deficiency 20–30 ng/                                        occur with RYGB;          normal; serum
                                                             2Urinary calcium              mL suggests                                                 prevalence                phosphorus may
                                                                                           insufficiency                                               unknown                   decrease, serum alkaline
                                                                                                                                                                                 phosphatase increases;

                                                                                                                                                                                                              L. Aills et al. / Surgery for Obesity and Related Diseases 4 (2008) S73-S108
                                                                                                                                                                                 PTH elevated
Vitamin E            Plasma alpha       5–20 ␮g/mL           Plasma lipids               ⬍5 ␮g/mL                    Uncommon                        Uncommon                  Low plasma alpha
                       tocopherol                                                                                                                                                tocopherol to plasma
                                                                                                                                                                                 lipids (0.8 mg/g total
                                                                                                                                                                                 lipid) should be used
                                                                                                                                                                                 with hyperlipidemia
Vitamin K            PT                 10–13 seconds        1DCP 2Plasma                Variable                    Uncommon                        Common with BPD/          PT is not a sensitive
                                                              phylloquinone                                                                            DS after 1 yr             measure of vitamin K
                                                                                                                                                                                 status
Zinc                 Plasma zinc        60–130 ␮g/dL         2RBC zinc                   Plasma zinc ⬍70 ␮g/dL       Uncommon, but increased         Common with BPD/          Monitor albumin levels
                                                                                                                       risk of low levels              DS after 1 yr; may        and interpret zinc
                                                                                                                       associated with obesity         occur with RYGB           accordingly, albumin is
                                                                                                                                                                                 primary binding protein
                                                                                                                                                                                 for zinc; no reliable
                                                                                                                                                                                 method of determining
                                                                                                                                                                                 zinc status is available;
                                                                                                                                                                                 plasma zinc is method
                                                                                                                                                                                 generally used; studies
                                                                                                                                                                                 cited in this report did
                                                                                                                                                                                 not adequately describe
                                                                                                                                                                                 methods of zinc analysis
Protein              Serum albumin      4 – 6 g/dL           2Serum prealbumin           Albumin ⬍3.0 g/dL           Uncommon                        Rare, but can occur       Half-life for prealbumin is
                       Serum total      6 – 8 g/dL            (transthyretin)            Prealbumin ⬍20 mg/dL                                          with RYGB, AGB,           2–4 d and reflects
                       protein                                                                                                                         and BPD/DS if             changes in nutritional
                                                                                                                                                       protein intake is         status sooner than
                                                                                                                                                       low in total intake       albumin, a nonspecific
                                                                                                                                                       or indispensable          protein carrier with a
                                                                                                                                                       amino acids               half-life of 22 d

  RYGB ⫽ Roux-en-Y gastric bypass; AGB ⫽ adjustable gastric banding; BPD/DS ⫽ biliopancreatic diversion/duodenal switch; PLP ⫽ pyridoxal-5’-phosphate; RBC ⫽ red blood cell; MMA ⫽
methylmalonic acid; tHcy ⫽ total homocysteine; CRT ⫽ creatinine; PPIs ⫽ protein pump inhibitors; FIGLU ⫽ formiminogluatmic acid; CBC ⫽ complete blood count; TIBC ⫽ total iron binding capacity;
Hgb ⫽ hemoglobin; Hct ⫽ hematocrit; RPB ⫽ retinol binding protein; PTH ⫽ parathyroid hormone; 25(OH)D ⫽ 25-hydroxyvitamin D; PT ⫽ prothrombin time; DCP ⫽ des-gamma-carboxypromthrom-
bin.
  In general, laboratory values should be reviewed annually or as indicated by clinical presentation. Laboratory normal values vary among laboratory settings and are method dependent. This chart provides
a brief summary of monitoring tools. See the Appendix for additional detail and diagnostic tools.
  © Jeanne Blankenship, MS RD. Used with permission.
L. Aills et al. / Surgery for Obesity and Related Diseases 4 (2008) S73-S108                             S79

Table 5
Suggested Postoperative Vitamin Supplementation
Supplement                                                       AGB               RYGB                 BPD/DS                 Comment

Multivitamin-mineral supplement
 ⴱA high-potency vitamin containing 100% of daily value for      100% of daily     200% of daily        200% of daily valueⴱ   Begin on day 1 after
    at least 2/3 of nutrients                                      valueⴱ            valueⴱ                                      hospital discharge
 Begin with chewable or liquid
 Progress to whole tablet/capsule as tolerated
 Avoid time-released supplements
 Avoid enteric coating
 Choose a complete formula with at least 18 mg iron, 400
    ␮g folic acid, and containing selenium and zinc in each
    serving
 Avoid children’s formulas that are incomplete
 May improve gastrointestinal tolerance when taken close to
    food intake
 May separate dosage
 Do not mix multivitamin containing iron with calcium
    supplement, take at least 2 hr apart
 Individual brands should be reviewed for absorption rate and
    bioavailability
 Specialized bariatric formulations are available

Additional cobalamin (B12)
  Available forms include sublingual tablets, liquid drops,
     mouth spray, or nasal gel/spray
  Intramuscular injection                                        —                 1000 ␮g/mo           —                      Begin 0–3 mo after
                                                                                                                                 surgery
  Oral tablet (crystalline form)                                 —                 350–500 ␮g/d         —
  Supplementation after AGB and BPD/DS may be required

Additional elemental calcium                                     1500 mg/d         1500– 2000 mg/d      1800– 2400 mg/d        May begin on day 1
  Choose a brand that contains calcium citrate and vitamin D3                                                                   after hospital
  Begin with chewable or liquid                                                                                                 discharge or
  Progress to whole tablet/capsule as tolerated                                                                                 within 1 mo after
                                                                                                                                surgery
  Split into 500–600 mg doses; be mindful of serving size on
    supplement label
  Space doses evenly throughout day
  Suggest a brand that contains magnesium, especially for
    BPD/DS
  Do not combine calcium with iron containing supplements:
    To maximize absorption
    To minimize gastrointestinal intolerance
    Wait ⱖ2 h after taking multivitamin or iron supplement
  Promote intake of dairy beverages and/or foods that are
    significant sources of dietary calcium in addition to
    recommended supplements, up to 3 servings daily
  Combined dietary and supplemental calcium intake ⬎1700
    mg/d may be required to prevent bone loss during rapid
    weight loss

Additional elemental iron (above that provided by mvi)           —                 Add a minimum        Add a minimum of       Begin on day 1 after
  Recommended for menstruating women and those at risk of                            of 18–27 mg/d        18–27 mg/d             hospital discharge
    anemia (total goal intake ⫽ 50-100 mg elemental iron/d)                          elemental            elemental
  Begin with chewable or liquid
  Progress to tablet as tolerated
  Dosage may need to be adjusted based on biochemical
    markers
  No enteric coating
  Do not mix iron and calcium supplements, take ⱖ2 h apart
  Avoid excessive intake of tea due to tannin interaction
  Encourage foods rich in heme iron
  Vitamin C may enhance absorption of non-heme iron sources
S80                                  L. Aills et al. / Surgery for Obesity and Related Diseases 4 (2008) S73-S108

Table 5
Continued
Supplement                                                      AGB               RYGB                 BPD/DS                   Comment

Fat-soluble vitamins                                            —                 —                    10,000 IU of vitamin A   May begin 2– 4
  With all procedures, higher maintenance doses may be                                                                           weeks after
                                                                —                 —                    2000 IU of vitamin D
     required for those with a history of deficiency                                                                             surgery
  Water-soluble preparations of fat-soluble vitamins are        —                 —                    300 ␮g of vitamin K
     available
  Retinol sources of vitamin A should be used to calculate
  dosage
  Most supplements contain a high percentage of beta
     carotene which does not contribute to vitamin A toxicity
  Intake of 2000 IU Vitamin D3 may be achieved with careful
     selection of multivitamin and calcium supplements
  No toxic effect known for vitamin K1, phytonadione
     (phyloquinone)
  Vitamin K requirement varies with dietary sources and
     colonic production
  Caution with vitamin K supplementation for patients
     receiving coagulation therapy
  Vitamin E deficiency has been suggested but is not
     prevalent in published studies

Optional B complex                                              1 serving/d       1 serving/d          1 serving/d              May begin on day 1
  B-50 dosage                                                                                                                    after hospital
  Liquid form is available                                                                                                       discharge
  Avoid time released tablets
  No known risk of toxicity
  May provide additional prophylaxis against B-vitamin
    deficiencies, including thiamin, especially for BPD/DS
    procedures as water-soluble vitamins are absorbed in the
    proximal jejunum
  Note ⬎1000 mg of supplemental folic acid, provided in
    combination with multivitamins, could mask B12
    deficiency

  Abbreviations as in Table 4.

which, in turn, causes metabolic changes that favor fat                       which are important for driving many of the biological
accumulation [23–25].                                                         processes that help to regulate body size [29 –31]. As the
   Several of the B-complex vitamins, important for appro-                    rate of noncompliance with prophylactic multivitamin sup-
priate metabolism of carbohydrate and neural functions that                   plementation increases, the rate of postoperative deficiency
regulate appetite, have been found to be deficient in some                    may increase almost twofold [32].
patients with morbid obesity [21,26,27]. Iron deficiencies,                      In the past, it has been thought that the specific nutri-
which would significantly hinder energy use, have been                        tional deficiencies commonly seen among malabsorptive
reported in nearly 50% of morbidly obese preoperative                         procedures would not be present in patients choosing a
candidates [21]. Zinc and selenium deficits have been re-                     purely restrictive surgery such as the adjustable gastric band
ported, as well as deficits in vitamins A, E, and C, all                      (AGB). However, poor eating behavior, low nutrient-dense
important antioxidants helpful in regulating energy produc-                   food choices, food intolerance, and a restricted portion size
tion and various other processes of body weight manage-                       can contribute to potential nutrient deficiencies in these
ment [19,26 –28].                                                             patients as well. Although the incidence of nutritional com-
   The risk of micronutrient depletion continues to be quite                  plications may be less frequent in this patient population, it
high, particularly after surgeries that affect the digestion and              would be detrimental to assume that they do not exist.
absorption of nutrients, such as Roux-en-Y gastric bypass                        It is important for the bariatric patient to take vitamin and
(RYGB) and biliopancreatic diversion with or without du-                      mineral supplements, not only to prevent adverse health
odenal switch (BPD/DS). RYGB increases the risk of vita-                      conditions that can arise after surgery, but because some
min B12 and other B vitamin deficits in addition to iron and                  nutrients such as calcium can enhance weight loss and help
calcium. BPD/DS procedures may also cause an increased                        prevent weight regain. The nutrient deficiency might be
risk of iron and calcium deficits, along with significant                     proportional to the length of the absorptive area bypassed
deficiencies in the fat-soluble vitamins A, D, E, and K,                      during surgical procedures and, to a lesser extent, to the
L. Aills et al. / Surgery for Obesity and Related Diseases 4 (2008) S73-S108                       S81

percentage of weight lost. Iron, vitamin B12, and vitamin D              postoperative changes nor include radioisotope labeling to
deficiencies, along with changes in calcium metabolism, are              measure absorption of key nutrients, and the subjects had
common after RYGB. Protein, fat-soluble vitamin, and                     undergone the procedure for reasons other than weight loss.
other micronutrient deficiencies, as well as altered calcium                It is unclear whether intestinal adaptation occurs after
metabolism, are most notably found after BPD/DS. Folate                  combination procedures and to what degree it affects long-
deficiency has been reported after AGB [33]. Thiamin de-                 term weight maintenance and nutrition status. Adaptation is
ficiency is common among all surgical patients with fre-                 a compensatory response that follows an abrupt decrease in
quent vomiting, regardless of the type of procedure per-                 mucosal surface area and has been well studied in short-
formed. Because many nutritional deficiencies progress                   bowel patients who require bowel resection [45]. The pro-
with time, patients should be monitored frequently and                   cess includes both anatomic and functional changes that
regularly to prevent malnutrition [29]. Reinforcement of                 increase the gut’s digestive and absorptive capacity. Al-
supplement compliance at each patient follow-up is also                  though these changes begin to take place in the early post-
important in the fight to enhance nutrition status and prevent           operative period, total adaptation may take up to three years
nutritional complications.                                               to complete. Adaptation in gastric bypass has not been
                                                                         considered in absorption or metabolic studies. This consid-
Weight loss and nutrient deficits: restriction                           eration could be important even when determining early and
versus malabsorption                                                     late macro- and micronutrient intake recommendations. The
                                                                         effect of pancreatic enzyme replacement therapy on vitamin
    Malabsorptive procedures such as the BPD/DS are                      and mineral absorption in this population is also unknown.
thought to cause weight loss primarily through the malab-                   Purely restrictive procedures such as the AGB can result
sorption of macronutrients, with as much as 25% of protein               in micronutrient deficiencies related to changes in dietary
and 72% of fat malabsorbed. Such primary malabsorption                   intake. It is commonly accepted that because no alteration is
results in concomitant malabsorption of micronutrients                   made in the absorptive pathway, malabsorption does not
[34,35]. Vitamins and minerals relying on fat metabolism,                occur as a result of AGB procedures. However, nutrient
including vitamins D, A, E, K, and zinc, may be affected                 deficits would be likely to occur because of the low nutrient
when absorption is impaired [36]. The decrease in gastro-                intake and avoidance of nutrient-rich foods in the early
intestinal transit time may also result in secondary malab-              months postoperatively and later possibly as a result of
sorption of a wide range of micronutrients related to by-                excessive band restriction. Food with high nutritional value
passing the duodenum and jejunum or limited contact with                 such as meat and fibrous fresh fruits and vegetables might
the brush border secondary to a short common limb. Other                 be poorly tolerated.
micronutrient deficiency concerns reported for patients                     Literature has been published that addresses the effect of
choosing a procedure with malabsorptive features include                 malabsorptive, restrictive, and combination surgical proce-
iron, calcium, vitamin B12, and folate.                                  dures on acute and long-term nutritional status. These stud-
    Nutrient deficiencies after RYGB can result from either              ies have attempted, for the most part, to indirectly determine
primary or secondary malabsorption or from inadequate                    the surgical impact on nutrition status by the evaluation of
dietary intake. A minimal amount of macronutrient malab-                 metabolic and laboratory markers. Although some studies
sorption is thought to occur. However, specific micronutri-              have included certain aspects of absorption, few have in-
ents appear to be malabsorbed postoperatively and present                cluded the necessary components to evaluate absorption of
as deficiencies without adequate vitamin and mineral sup-                a prescribed and/or monitored diet in a controlled metabolic
plementation. Retrospective analyses of patients who have                setting.
undergone gastric bypass have revealed predictable micro-                   The following sections examine the pre- and postopera-
nutrient deficiencies, including iron, vitamin B12 and folate            tive risks for nutritional deficiencies associated with RYGB,
[26,27–39]. Case reports have also shown that thiamin de-                BPD/DS, and AGB. It is important for all members of the
ficiency can develop, especially when persistent postopera-              medical team to increase their awareness of the nutritional
tive vomiting occurs [40 – 43].                                          complications and challenges that lie ahead for the patient.
    Few studies that measure absorption after measured and               Continued review of current research, by the medical team,
quantified intake have been published. It can be hypothe-                regarding advances in nutrition science beyond the bound-
sized that the bypassed duodenum and proximal jejunum                    aries of the present report cannot be emphasized enough.
negatively affect nutrient assimilation. Bradley et al. [44]
studied patients who had undergone total gastrectomy, the
                                                                         Thiamin (vitamin B1)
procedure from which the RYGB evolved. The researchers
found that most nutritional status changes in patients were                 Beriberi is a thiamin deficiency that can affect various
most likely due to changes in intake versus malabsorption.               organ systems, including the heart, gastrointestinal tract,
These balance studies were conducted in a controlled re-                 and peripheral and central nervous systems. Although the
search setting; however, they did not measure pre- and                   condition is generally considered rare, a number of reported,
S82                               L. Aills et al. / Surgery for Obesity and Related Diseases 4 (2008) S73-S108

and possibly a much greater number of unreported or un-                    suggested a need for preoperative thiamin testing, as well as
diagnosed cases, of beriberi have occurred among individ-                  thiamin repletion by diet or supplementation to reduce the
uals who have undergone surgery for morbid obesity. Early                  risk of “bariatric” beriberi postoperatively.
detection and prompt treatment of thiamin deficits in these
individuals can help to prevent serious health consequences.               Postoperative risk. Beriberi has been observed after gastric
If beriberi is misdiagnosed or goes undetected for even a                  restrictive and malabsorptive procedures. A number of cases
short period, the bariatric patient can develop irreversible               of Wernicke-Korsakoff syndrome (WKS), as well as periph-
neuromuscular disorders, permanent defects in learning and                 eral neuropathy, have been reported for patients having
short-term memory, coma, and even death. Because of the                    undergone vertical banded gastroplasty [53– 61]. A few
life-altering and potentially life-threatening nature of a thi-            incidences of WKS have also been reported after AGB
amin deficiency, it is important that healthcare professionals             [43,62,63]. Additionally, reports of thiamin deficiencies and
in the field of bariatric surgery have knowledge of the                    WKS after RYGB [40,41,64 –73] and several cases of WKS
etiology of the condition, and its signs and symptoms,                     and neuropathy in patients who had undergone BPD [74]
treatment, and prevention.                                                 have been published. Many more cases of WKS are be-
                                                                           lieved to have occurred with bariatric procedures that have
Etiology of potential deficiency. Thiamin is a water-soluble               either not been reported or have been misdiagnosed because
vitamin that is absorbed in the proximal jejunum by an                     of limited knowledge regarding the signs and symptoms of
active (saturable, high-affinity) transport system [46,47]. In             acute or severe thiamin deficits. Because many foods are
the body, thiamin is found in high concentrations in the                   fortified with thiamin, beriberi has been nearly eradicated
brain, heart, muscle, liver, and kidneys. However, without                 throughout the world, except for patients with severe alco-
regular and sufficient intake, these tissues become rapidly                holism, severe vomiting during pregnancy (hyperemesis
devoid of thiamin [46,47]. The total amount of thiamin in                  gravidarium), or those malnourished and starved. For this
the body of an adult is approximately 30 mg, with a half-life              reason, few healthcare professionals, until recently, have
of only 9 –18 days. Persistent vomiting, a diet deficient in               had a patient present with beriberi.
the vitamin, or the body’s excessive utilization of thiamin                    According to the published reports of thiamin deficits
use can result in a severe state of thiamin depletion within               after bariatric procedures, most patients develop such defi-
only a short period, producing symptoms of beriberi                        ciencies in the early postoperative months after an episode
[46 – 48].
                                                                           of intractable vomiting. Nausea and vomiting are relatively
    Bariatric surgery increases the risk of beriberi through ex-
                                                                           common after all bariatric procedures early in the postop-
acerbation of pre-existing thiamin deficits, low nutrient intake,
                                                                           erative period. Thiamin stores in the body are small and
malabsorption, and episodes of nausea and vomiting [49 –51].
                                                                           maintenance of appropriate thiamin levels requires daily
Chronic or acute thiamin deficiencies in bariatric patients often
                                                                           replenishment. A deficiency of thiamin for only a couple of
present with symptoms of peripheral neuropathy or Wer-
                                                                           weeks or less, caused by persistent vomiting, can deplete
nicke’s encephalopathy and Korsakoff’s psychoses [21,48 –
                                                                           thiamin stores. Symptoms of WKS were reported in a
54]. Early diagnosis of the signs and symptoms of these con-
                                                                           RYGB patient after only two weeks of persistent vomiting
ditions is extremely important to prevent serious adverse health
                                                                           [67].
consequences. Even if treatment is initiated, recovery can be
                                                                               Bariatric beriberi can also develop in postoperative patients
incomplete, with cognitive and/or neuromuscular impairments
                                                                           who are given infusate containing dextrose without thiamin
persisting long term or permanently.
                                                                           and other vitamins, which is often the case for patients in
Signs, symptoms, and treatment of deficiency (see                          critical care units, postoperative patients with complications
Appendix, Table A1)                                                        interfering with the ingestion of food, or patients dehydrated
                                                                           from persistent vomiting. Malnutrition caused by a lack of
Preoperative risk. The risk of the development of beriberi                 appetite and dietary intake postoperatively also contributes to
after bariatric surgery is far greater for individuals present-            bariatric beriberi, as does noncompliance in taking postopera-
ing for surgery with low thiamin levels. Investigators at the              tive vitamin supplements.
Cleveland Clinic of Florida reported that 15% of their pre-                    Although most cases of beriberi occur in the early post-
operative bariatric patients had deficiencies in thiamin be-               operative periods, cases of patients with severe thiamin
fore surgery [52]. A study by Flancbaum et al. [21] similarly              deficiency more than one year after surgery have been
found that 29% of their preoperative patients had low thia-                reported. One study reported WKS in association with al-
min levels. Data obtained by that study also showed a                      cohol abuse 13 years after RYGB [75]. Other conditions
significant difference between ethnicity and preoperative                  contributing to late cases of bariatric beriberi include a
thiamin levels. Although only 6.7% of whites presented                     thiamin-poor diet, a diet high in carbohydrates, anorexia,
with thiamin deficiencies before surgery, nearly one third                 and bulimia [46 – 48].
(31%) of African Americans and almost one half (47%) of
Hispanics had thiamin deficits. The results of these studies               Suggested supplementation. Because of the greater likeli-
L. Aills et al. / Surgery for Obesity and Related Diseases 4 (2008) S73-S108                      S83

hood of low dietary thiamin intake, patients should be sup-              tis, resected small bowel, elderly patients) can be impaired,
plemented with thiamin. This is usually accomplished                     causing an IF deficiency. Subsequent vitamin B12 deficiency
through daily intake of a multivitamin. Most multivitamins               (pernicious anemia) occurs without IF production or use,
contain thiamin at 100% of the daily value. Patients having              because IF is needed to absorb vitamin B12 in the terminal
episodes of nausea and vomiting and those who are anorec-                ileum [77]. Factors that increase the risk of vitamin B12
tic might require sublingual, intramuscular, or intravenous              deficiency relevant to bariatric surgery include the follow-
thiamin to avoid depletion of thiamin stores and beriberi.               ing:
Caution should be used when infusing bariatric patients
                                                                                An inability to release protein-bound vitamin B12
with solutions containing dextrose without additional vita-
                                                                                  from food, particularly in hypochlorhydria and
mins and thiamin, because an increase in glucose utilization
                                                                                  atrophic gastritis
without additional thiamin can deplete thiamin stores [76].
                                                                                Malabsorption due to inadequate IF in pernicious
    Thiamin deficiency in bariatric patients is treated with
                                                                                  anemia
thiamin, together with other B-complex vitamins and mag-
                                                                                Gastrectomy and gastric bypass
nesium, for maximal thiamin absorption and appropriate
                                                                                Resection or disease of terminal ileum
neurologic function [46 – 48]. Early symptoms of neuropa-
                                                                                Long-term vegan diet
thy can often be resolved by providing the patient with oral
                                                                                Medications, such as neomycin, metformin, colch-
thiamin doses of 20 –30 mg/d until symptoms disappear. For
                                                                                  icines, medications used in the management of
more advanced signs of neuropathy or for individuals with
                                                                                  bowel inflammation and gastroesophageal reflux
protracted vomiting, 50 –100 mg/d of intravenous or intra-
                                                                                  and ulcers (e.g., proton pump inhibitors) and anti-
muscular thiamin may be necessary for resolution or im-
                                                                                  convulsant agents [79]
provement of symptoms or for the prevention of such.
Patients with WKS generally require ⱖ100 mg thiamin                         Cobalamin stores are known to exist for long periods
administered intravenously for several days or longer, fol-              (3–5 yr) and are dependent on dietary repletion and daily
lowed by intramuscular thiamin or high oral doses until                  depletion. However, gastric bypass patients have both a
symptoms have resolved or significantly improved. This can               decreased production of stomach acid and a decreased avail-
require months to years. Some patients might have to take                ability of IF; thus, a vitamin B12 deficiency could develop
thiamin for life to prevent the reoccurrence of neuropathy.              without appropriate supplementation. Because the typical
                                                                         absorption pathway cannot be relied on, the surgical weight
Vitamin B12 and folate                                                   loss patient must rely on passive absorption of B12, which
                                                                         occurs independent of IF.
   Vitamin B12 (cobalamin) and folate (folic acid) are both
involved in the maturation of red blood cells and are com-               Signs, symptoms, and treatment of deficiency (see
monly discussed in the literature together. Over time, a                 Appendix, Table A3)
deficiency in either vitamin B12 or folate can lead to mac-
                                                                         Preoperative risk. Several medications common to preop-
rocytic anemia, a condition characterized by the production
                                                                         erative bariatric patients have been noted to affect preoper-
of fewer, but larger, red blood cells and a decreased ability
                                                                         ative vitamin B12 absorption and stores. Of patients taking
to carry oxygen. Most (95%) cases of megaloblastic anemia
                                                                         metformin, 10 –30% present with reduced vitamin B12 ab-
(characterized by large, immature, abnormal, undifferenti-
                                                                         sorption [80]. Additionally, patients with obesity have a
ated red blood cells in bone marrow) are attributed to
                                                                         high incidence of gastroesophageal reflux disease, for which
vitamin B12 or folate deficiency [77].
                                                                         they take proton pump inhibitors, thus increasing the poten-
                                                                         tial to develop a vitamin B12 deficiency.
Vitamin B12
                                                                             Flancbaum et al. [21] conducted a retrospective study of
Etiology of potential deficiency. RYGB patients have both                379 (320 women and 59 men) pre-operative patients. Vita-
incomplete digestion and release of vitamin B12 from pro-                min B12 deficiency was reported as negative in all patients
tein foods. With a significant decrease in hydrochloric acid,            of various ethnic backgrounds [21]. No clinical criteria or
pepsinogen is not converted into pepsin, which is necessary              symptoms for vitamin B12 deficiency were noted. In the
for the release of vitamin B12 from protein [78]. Because                general population, 5–10% present with neurologic symp-
AGB patients have an artificial restriction, yet complete use            toms with vitamin B12 levels of 200 – 400 pg/mL. Among
of the stomach, and BPD patients do not have as great a                  preoperative gastric bypass patients, Madan et al. [27] found
restriction in stomach capacity and parietal cells as RYGB               that 13% (n ⫽ 59) of patients were deficient in vitamin B12.
patients, the reduction in hydrochloric acid and subsequent              In a comparison of patients presenting for either RYGB or
vitamin B12 deficiency is not as prevalent with these two                BPD, Skroubis et al. [81] recently reported that preoperative
procedures.                                                              vitamin B12 levels were low-normal in both groups. It
   Intrinsic factor (IF) is produced by the parietal cells of            would be prudent to screen for, and treat, IF deficiency
the stomach and in certain conditions (e.g., atrophic gastri-            and/or vitamin B12 deficiency in all patients preoperatively,
S84                             L. Aills et al. / Surgery for Obesity and Related Diseases 4 (2008) S73-S108

but it is essential for RYGB patients so as not to hasten the            some patients may experience extreme delusions, halluci-
development of a potential postoperative deficiency.                     nations, and, even, overt psychosis [93].
Postoperative risk. Vitamin B12 deficiency has been fre-                 Suggested supplementation. Because of the frequent lack of
quently reported after RYGB. Schilling et al. [82] estimated             symptoms of vitamin B12 deficiency, the suggested dili-
the prevalence of vitamin B12 deficiency to be 12–33%.                   gence in following up or treating these values among those
Other researchers have suggested a much greater prevalence               asymptomatic patients has been questioned. The decision
of B12 deficiency in up to 75% of postoperative RYGB                     not to supplement or routinely screen patients for B12 defi-
patients; however, most reports have cited approximately                 ciency should be examined very carefully, given the risk of
35% of postoperative RYGB patients as vitamin B12 defi-                  irreversible neurologic damage if vitamin B12 goes un-
cient [82– 87]. Brolin et al. [87] reported that low levels of           treated for long periods. At least one case report has been
vitamin B12 might be seen as soon as six months after                    published of an exclusively breastfed infant with vitamin
bariatric surgery, but most often occurring more than one                B12 deficiency who was born of an asymptomatic mother
year postoperatively as liver stores become depleted. Sk-                who had undergone gastric bypass surgery [94].
roubis et al. [88] predicted that the deficiency will most                   Deficiency of vitamin B12 is typically defined at levels
likely occur 7 months after RYGB and 7.9 months after                    ⬍200 pg/mL. However, about 50% of patients with obvious
BPD/DS, although their research did not consider compro-                 signs and symptoms of deficiency have normal vitamin B12
                                                                         levels [31]. Kaplan et al. [95] reported that vitamin B12
mised preoperative status and its correlation to postopera-
                                                                         deficiency usually resolves after several weeks of treatment
tive deficiency. After the first postoperative year, the prev-
                                                                         with 700 –2000 ␮g/wk. Rhode et al. [96] found that a
alence of vitamin B12 deficiency appears to increase yearly
                                                                         dosage of 350 – 600 ␮g/d of oral B12 prevented vitamin B12
in RYGB patients [89].
                                                                         deficiency in 95% of patients and an oral dose of 500 ␮g/d
   Although the body’s storage of vitamin B12 is significant
                                                                         was sufficient to overcome an existing deficiency as re-
(⬃2000 ␮g) compared with daily needs (2.4 ␮g/d), this
                                                                         ported by Brolin et al. [87] in a similar study. Therefore,
particular deficiency has been found within 1–9 years of                 supplementation of RYGB patients with 350 –500 ␮g/d may
gastric bypass surgery [29]. Brolin et al. [84] reported that            prevent most postoperative vitamin B12 deficiency.
one third of RYGB patients are deficient at four years                       While most vitamin B12 in normal adults is absorbed in
postoperatively. However, non-surgical variables were not                the ileum in the presence of IF, approximately 1% of sup-
explored, and many patients might have had preoperative                  plemented B12 will be absorbed passively (by diffusion)
values near the lower end of the normal range. Ocon Breton               along the entire length of the (non-bypassed) intestine by
et al. [90] compared micronutrient deficiencies among two-               surgical weight loss patients given a high-dose oral supple-
year postoperative BPD/DS and RYGB patients and found                    ment [97]. Thus, the consumption of 350 –500 ␮g yields a
that all nutritional deficiencies were more common among                 3.5–5.0-␮g absorption, which is greater than the daily re-
BPD/DS patients, except for vitamin B12, for which the                   quirement. Although the use of monthly intramuscular in-
deficiency was more common among the RYGB patients                       jections or a weekly oral dose of vitamin B12 is common
studied. A lack of B12 deficiency among BPD/DS patients                  among practices, it relies on patient compliance. Practitio-
might result from a better tolerance of animal proteins in a             ners should assess the patient’s preference and the potential
larger pouch, greater pepsin/gastric acid production to re-              for compliance when considering a daily, weekly, or
lease protein-bound B12, and increased availability and in-              monthly regimen of B12 supplementation. In addition to oral
teraction of IF with the pouch contents.                                 supplements or intramuscular injections, nasal sprays and
   Experts have noted the significance of subclinical defi-              sublingual sources of vitamin B12 are also available. Pa-
ciency in the low-normal cobalamin range in nongastric                   tients should be monitored closely for their lifetime, because
bypass patients who do not exhibit clinical evidence of                  severe anemia can develop with or without supplementation
deficiency. The methylmalonic acid (MMA) assay is the                    [98].
preferred marker of B12 status because metabolic changes
often precede low B12 levels in the progression to defi-                 Folate
ciency. Serum B12 assays may miss as much as 25–30% of
                                                                         Etiology of potential deficiency. Factors that increase the
B12 deficiencies, making them less reliable than the MMA
                                                                         risk of folic acid deficiency relevant to bariatric surgery
assay [91]. It has been suggested that early signs of vitamin            include the following:
B12 deficiency can be detected if the serum levels of both
MMA and homocysteine are measured [91]. Vitamin B12                             Inadequate dietary intake
deficiency after RYGB has been associated with megalo-                          Noncompliance with multivitamin supplementation
blastic anemia [92]. Some vitamin B12-deficient patients                        Malabsorption
develop significant symptoms, such as polyneuropathy, par-                      Medications (anticonvulsants, oral contraceptives,
esthesia, and permanent neural impairment. On occasion,                            and cancer treating agents) [79].
L. Aills et al. / Surgery for Obesity and Related Diseases 4 (2008) S73-S108                           S85

   Folic acid stores can be depleted within a few months                  corrects the deficiency in the vast majority of postoperative
postoperatively unless replenished by a multivitamin supple-              bariatric patients [103]. Therefore, persistent folate defi-
ment and dietary sources (i.e., green leafy vegetables, fruits,           ciency might indicate a patient’s lack of compliance with
organ meats, liver, dried yeast, and fortified grain products).           the prescribed vitamin protocol [32].
                                                                             It is common knowledge that folic acid deficiency among
Signs, symptoms, and treatment of deficiency (see                         pregnant women has been associated with a greater risk of
Appendix, Table A4)                                                       neural tube defects in newborns. Consistent supplementa-
                                                                          tion and monitoring among women of child-bearing age,
Preoperative risk. The goals of the 1998 Food and Drug                    including pre- and postoperative bariatric patients is vital in
Administration policy, requiring all enriched grain products              an effort to prevent the possibility of neural tube defects in
to be fortified with folate, included increasing the average              the developing fetus.
American diet by 100 ␮g folate daily and decreasing the                      Because folate does not affect the myelin of nerves,
rate of neural tube defects in childbearing women [99].                   neurologic damage is not as common with folate, such as is
Bentley et al. [100] reported that the proportion of women                the case for vitamin B12 deficiency. In contrast, patients
aged 15– 44 years old (in the general population) who meet                with folate deficiency often present with forgetfulness, irri-
the recommended dietary intake of 400 ␮g/d folate varies                  tability, hostility, and even paranoid behaviors [29]. Similar
between 23% and 33%. With the increasing popularity of                    to that evidenced with vitamin B12, most postoperative
high protein/low carbohydrate diets, one cannot assume that               RYGB patients who are folate deficient are asymptomatic or
preoperative patients consume dietary sources of folate                   have subclinical symptoms; therefore, these deficient states
through fortified grain products, fruits, and vegetables. Boy-            may not be easily identified.
lan et al. [26] found folate deficiencies preoperatively in
56% of RYGB patients studied.                                             Suggested supplementation. Even though folate absorption
                                                                          occurs preferentially in the proximal portion of the small
Postoperative risk. Although it has been observed that fo-                intestine, it can occur along the entire length of the small bowel
late deficiency after RYGB surgery is less common than B12                with postoperative adaptation. Therefore, it is generally agreed
deficiency and is thought to occur because of decreased                   that folate deficiency is corrected with 1000 mg/d folic acid
dietary or multivitamin supplement intake, low serum folate               [32] and is preventable with supplementation that provides
levels have been cited from 6% to 65% among RYGB                          200% of the daily value (800 ␮g). This level can also benefit
patients [26,86,101]. Additionally, folate deficiencies have              the fetus in a female patient unaware of her postoperative
occurred postoperatively, even with supplementation. Boy-                 pregnancy. Folate supplementation ⬎1000 mg/d has not
lan et al. [26] found that 47% (n ⫽ 17) of RYGB patients                  been recommended because of the potential for masking
had low folate levels six months postoperatively and 41%                  vitamin B12 deficiency. Carmel et al. [104] suggested that
(n ⫽ 17) had low levels at one year. This deficiency oc-                  homocysteine is the most sensitive marker of folic acid
curred despite patient adherence to taking a multivitamin                 status, in conjunction with erythrocyte folate. Although
supplement that contained at least the daily value for folate,            folic acid deficiency could potentially occur among post-
400 ␮g [26]. Postoperative bariatric patients with rapid                  operative bariatric surgery patients, it has not been seen
weight loss might have an increased risk of micronutrient                 widely in recent studies, especially when patients have
deficiencies. MacLean et al. [86] reported that 65% of                    been compliant with postoperative multivitamin supple-
postoperative patients had low folate levels. These same                  mentation. Therefore, it is imperative to closely follow
patients exhibited additional B vitamin deficiencies: 24%                 folic acid both pre- and postoperatively, especially in
vitamin B12 and 50% thiamin [86]. An increased risk of                    those patients suspected to be noncompliant with their
deficiency has also been noted among AGB patients, pos-                   multivitamin supplementation.
sibly because of decreased folate intake. Gasteyger et al.
[33] found a significant decrease in serum folate levels
                                                                          Iron
(44.1%) between the baseline and 24-month postoperative
measurements.                                                                 Much of the iron and surgical weight loss research con-
   Dixon and O’Brien [101] reported elevated serum ho-                    ducted to date has been generated from a limited number of
mocysteine levels in patients after bariatric surgery, regard-            surgeons and scientists; however, the data have consistently
less of the type of procedure (restrictive or malabsorptive).             pointed toward the risk of iron deficiency and anemia after
Elevated homocysteine levels can indicate, not only low                   bariatric procedures. Iron deficiency is defined as a decrease
folate levels and a greater risk of neural tube defects, but can          in the total iron body content. Iron deficiency anemia occurs
also be indicative of an independent risk factor for heart                when erythropoiesis is impaired as a result of the lack of
disease and/or oxidative stress in the nonbariatric popula-               iron stores. In the absence of anemia, iron deficiency is
tion [102]. However, unlike iron and vitamin B12, the folate              usually asymptomatic. Fatigue and a diminished capacity to
contained in the multivitamin supplementation essentially                 exercise, however, are common symptoms of anemia.
S86                              L. Aills et al. / Surgery for Obesity and Related Diseases 4 (2008) S73-S108

Etiology of potential deficiency. As with other vitamins and              didates have also been found to be iron deficient preopera-
minerals, the possible reasons for iron deficiency related to             tively. In one retrospective study of consecutive cases (n ⫽
surgical weight loss are multifactorial and not fully ex-                 379), 44% of bariatric surgery candidates were iron defi-
plained in the literature. Iron deficiency can be associated              cient [21]. In this report, men were more likely than women
with malabsorptive procedures, combination procedures,                    to be anemic (40.7% versus 19.1%), as determined by ab-
and AGB, although the etiology of the deficiency is likely to             normal hemoglobin values. Women, however, were more
be unique with each procedure. Although the absorption of                 likely to have abnormal ferritin levels. Anemia and iron
iron can occur throughout the small intestine, it is most                 deficiency were more common in patients ⬍25 years of age
efficient in the duodenum and proximal jejunum, which is                  compared with those ⬎60 years of age. Of these, 79% of
bypassed after RYGB, leading to decreased overall absorp-                 younger patients versus 42% of older patients presented
tion. Important receptors in the apical membrane of the                   with preoperative iron deficiency, as determined by low
enterocyte, including duodenal cytochrome b are involved                  serum iron values. Another study found iron levels to be
in the reduction of ferric iron and subsequent transporting of            abnormal in 16% of patients, despite a low proportion of
iron into the cell [105]. The effect of bariatric surgery on              patients for whom data were available (64%). These studies
these transporters has not been defined, but it is likely that,           are in contrast to earlier reports of limited preoperative iron
at least initially, fewer receptors are available to transport            deficiency [32,107].
iron. With malabsorptive procedures, there is likely a de-
crease in transit time during which dietary iron has less                 Postoperative risk. Iron deficiency is common after gastric
contact with the lumen, in addition to the bypass of the                  bypass surgery, with reports of deficiency ranging from 20% to
duodenum, resulting in decreased absorption. In RYGB                      49% [32,98,107,108]. Up to 51% of female patients in one
procedures, decreased absorption is coupled with reduced                  series were iron deficient, confirming the high-risk nature of
dietary intake of iron-rich foods, such as meats, enriched                this population [87]. Among patients with super obesity un-
grains, and vegetables. Those patients who are able to tol-               dergoing RYGB with varying limb length, iron deficiency has
erate meat have been shown to have a lower risk of iron                   been identified in 49 –52% and anemia in 35–74% of subjects
deficiency [38]; however, patient tolerance varies consider-              up to 3 years postoperatively [84].
ably and red meat, in particular, is often cited as a poorly                  In one study, the prevalence of iron deficiency was sim-
tolerated food source. Iron-fortified grain products are often            ilar among RYGB and BPD subjects. Skroubis et al. [88]
limited because of the emphasis on protein-rich foods and                 followed both RYGB and BPD subjects for five years. The
restricted carbohydrate intake. Finally, decreased hydro-                 ferritin levels at two years were significantly different be-
chloric acid production in the stomach after RYGB [106]                   tween the two groups, with 38% of RYGB versus 15% of
can affect the reduction of iron from the ferric (Fe3⫹) to the            BPD subjects having low levels. The percentage of patients
absorbable ferrous state (Fe2⫹). Notably, vitamin C, found                included in the follow-up data decreased considerably in
in both dietary and supplemental sources, can enhance iron                both groups and must be taken into account. Although data
absorption of non-heme iron, making it a worthy recom-                    for 70 RYGB subjects and 60 BPD subjects were recorded
mendation for inclusion in the postoperative diet [39].                   at one year, only eight and one subject remained in the
                                                                          groups, respectively, at five years. It is difficult to comment
                                                                          on the iron status and other clinical parameters, given the
Signs, symptoms, and treatment of deficiency (see
                                                                          weight of the data. For example, the investigators reported
Appendix, Table A5)
                                                                          that 100% of BPD subjects were deficient in hemoglobin,
Preoperative risk. The prevalence of iron deficiency in the               iron, and ferritin. However, only one subject remained,
United States is well documented. Premenopausal women                     making the later results nongeneralizable. Additional stud-
are at increased risk of deficiency because of menstrual                  ies investigating iron absorption and status are warranted for
losses, especially when oral contraceptives are not used.                 BPD/DS procedures.
The use of oral contraceptives alone decreases blood loss                     Menstruating women and adolescents who undergo bariat-
from menstruation by as much as 60% and decreases the                     ric surgery might require additional iron. One randomized
recommended daily allowance to 11 mg/d (instead of 15                     study of premenopausal RYGB women (n ⫽ 56) demonstrated
mg/d) [105]. Women of child-bearing age comprise a large                  that 320 mg of supplemental oral iron (ferrous sulfate) given
percentage (⬎80%) of the bariatric surgery cases performed                twice daily prevented the development of iron deficiency but
each year. The propensity of this population to be at risk of             did not protect against the development of anemia [107]. No-
iron deficiency and related anemia is relatively independent              tably, those patients who developed anemia were not regularly
of bariatric surgery and, thus, should be evaluated before the            taking their iron supplements (ⱖ5 times/wk) during the period
procedure to establish baseline measures of iron status and               preceding diagnosis. In that study, a significant correlation was
to treat a deficiency, if indicated.                                      found between the resolution of iron deficiency and adhering to
   Women, however, are not the only group at risk of iron                 the prescribed oral iron supplement regimen. Ferritin levels
deficiency, obese men and younger (⬍25 yr) surgical can-                  had decreased at two years in the untreated group, but those in
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